What is the difference between a database and a data warehouse?
Aren\'t they the same thing, or at least written in the same thing (ie. Oracle RDBMS)?
A data warehouse is a TYPE of database.
In addition to what folks have already said, data warehouses tend to be OLAP, with indexes, etc. tuned for reading, not writing, and the data is de-normalized / transformed into forms that are easier to read & analyze.
Some folks have said "databases" are the same as OLTP -- this isn't true. OLTP, again, is a TYPE of database.
Other types of "databases": Text files, XML, Excel, CSV..., Flat Files :-)